1. Leiden University Medical Center; Department of Obstetrics; K-06-35, P.O.Box 9600 2300 RC Leiden The Netherlands
2. Prenatal Diagnosis Unit, Genetic Institute, Tel Aviv Sourasky Medical Center, Affiliated to Department of Obstetrics & Gynecology, Sackler Faculty of Medicine; Tel Aviv University; Israel
3. Praenatal-Medizin und Genetik; Düsseldorf Germany
4. Immunology and Autoimmunity Unit, Department Clinical Pathology; Hospital Prof. Fernando Fonseca E.P.E.; Amadora Portugal
5. Division of Obstetrics and Gynecology; University Hospital La Paz, Universidad Autónoma de Madrid; Madrid Spain
6. Onze Lieve Vrouw Gasthuis; Amsterdam The Netherlands
7. Royal Maternity Hospital; Belfast UK
8. Medical University Vienna; Department of Obstetrics and Gynecology, Division of Obstetrics and Feto-Maternal Medicine; Vienna Austria
9. Department of Obstetrics and Feto-maternal Medicine; Medical University of Vienna, Vienna General Hospital; Vienna Austria
10. 1st Department of Obstetrics and Gynecology; Medical University of Warsaw; Warsaw Poland
11. Unitat de Biologia, Departament de Biologia Cellular, Fisiologia i, Immunologia; Universitat Autònoma de Barcelona; Bellaterra Barcelona Spain
12. Dept. of Ob/Gyn and Centre for Perinatal and Reproductive Medicine; Santa Maria della Misericordia University Hospital; San Sisto Perugia Italy
13. The Ian Donald Fetal Medicine Centre; Southern General Hospital; Glasgow UK
14. The Fetal Medicine Center and Ultrasound Unit, Department of Obstetrics & Gynecology, First Faculty of Medicine; Charles University in Prague; Prague Czech Republic
15. Rigshospitalet, Copenhagen University Hospital; Center for Fetal Medicine and Pregnancy; The Juliane Marie Center Copenhagen Denmark